Not Applicable
1. Field of the Invention
This invention relates generally to hand drills, and more particularly to a hand drill having geometrically correct guide surfaces aligned with an axis of a chuck of the hand drill thereby allowing the hand drill to be used to drill precision holes in a workpiece without the use of a drill press.
2. Description of Related Art
Conventional hand drills are typically shaped like a pistol. The drill housing is rounded in shape, which provides a comfortable fit in the user""s hand, but does not lend to the accuracy of the drill. The prior art hand drills depend upon the hand guidance and stability of the user for accuracy in drilling. If increased precision is required, an accessory must typically be attached to the drill; or the user must use a drill press instead of a hand drill.
The following art defines the present state of this field:
D. Kelbel, U.S. Pat. No. 3,664,754, teaches a bubble type alignment device for use in upon and with hand drills comprising bubble type level chambers appropriately shaped and operably mounted to a conventional hand drill allowing a first such level which is aligned parallel to the drill bit and a second such level which is aligned perpendicular to the first.
L. E. Pugsley, U.S. Pat. No. 3,107,556, teaches a hand drill and drill guide combination applied to a motor driven drill.
Haddon, U.S. Pat. No. 4,729,698, teaches a portable electrical power tool constituted by two cooperating main components, namely, a power head of predetermined exterior cross-sectional shape and a sleeve with interior surfaces mating to the power head to afford relative sliding movement, but not relative rotational movement of the two.
Cornair, U.S. Pat. No. 3,835,527, teaches a universal, multi-purpose support table for simultaneously supporting a work piece and at least one power or other tool at various horizontal and vertical positions with respect to the work piece.
Converse, U.S. Pat. No. 3,827,822, teaches a guided tool for controlling the attack of a tool against a work face wherein a keyway slidably mates with a key on a tool housing, so that the tool is guided toward a work piece in a predetermined attitude.
Capotosto et al., U.S. Pat. No. 5,147,162, teaches a self-guidable portable electric drill having as an integral appendage of the motor housing a V-grooved channel which is instrumental in guiding the drill on an axis perpendicular to the work surface when the trough of the V-groove is butted against, and slidably moved downwardly along the blade of the common try or combination square standing perpendicularly on the work surface.
Vesely, U.S. Pat. No. 4,566,169, teaches a building set including at least a drive motor, a spindle stock and a support element for holding these elements.
The prior art teaches hand drills having various attachments for making precision cuts. However, the prior art does not teach a hand drill having a geometrically correct housing that allows the hand drill to make precision cuts without attachments. The present invention fulfills these needs and provides further related advantages as described in the following summary.
The present invention teaches certain benefits in construction and use which give rise to the objectives described below.
The present invention provides a hand drill for rotating a cutter. The hand drill includes a housing having a motor therein. The housing has a first end and a second end. A first planar surface of the housing extends between the first and second ends, the first planar surface being parallel to an axis of rotation of a chuck driven by the motor and extending from the first end of the housing. A second planar surface of the housing also extends between the first and second ends and is parallel to the axis. The first and second planar surfaces are spaced a first and second predetermined distance, respectively, from the axis, the second predetermined distance being different than the first predetermined distance. The first and second planar surfaces enable the hand drill to be used to drill precision holes without the use of a drill press.
A primary objective of the present invention is to provide a hand drill having advantages not taught by the prior art.
Another objective is to provide a hand drill that enables a user to make precision cuts without the use of a drill press.
Other features and advantages of the present invention will become apparent from the following more detailed description, taken in conjunction with the accompanying drawings, which illustrate, by way of example, the principles of the invention.